Install percona-toolkit failture

Hi all. I tried to install percona toolkit but always get the error information. Any advance? Thanks!

[root@435938-db2 anemometer]# yum install percona-toolkit-2.2.11-1.noarch.rpm
Loaded plugins: downloadonly, rhnplugin, security
This system is receiving updates from RHN Classic or RHN Satellite.
epel | 3.7 kB 00:00
rackspace-rhel-x86_64-server-5-common | 871 B 00:00
rackspace-rhel-x86_64-server-5-php-5.2 | 871 B 00:00
rackspace-rhel-x86_64-server-5-php-5.3 | 871 B 00:00
rhel-x86_64-server-5 | 1.3 kB 00:00
rhn-tools-rhel-x86_64-server-5 | 1.1 kB 00:00
Excluding Packages in global exclude list
Finished
Excluding Packages from Rackspace - RHEL (v. 5 for 64-bit x86_64) - Common
Finished
Excluding Packages from Rackspace - RHEL (v. 5 for 64-bit x86_64) - PHP 5.2
Finished
Excluding Packages from Rackspace - RHEL (v. 5 for 64-bit x86_64) - PHP 5.3
Finished
Excluding Packages from Red Hat Enterprise Linux (v. 5 for 64-bit x86_64)
Finished
Excluding Packages from Red Hat Network Tools for RHEL Server (v.5 64-bit x86_64)
Finished
Setting up Install Process
Examining percona-toolkit-2.2.11-1.noarch.rpm: percona-toolkit-2.2.11-1.noarch
Marking percona-toolkit-2.2.11-1.noarch.rpm to be installed
Resolving Dependencies
→ Running transaction check
—> Package percona-toolkit.noarch 0:2.2.11-1 set to be updated
→ Finished Dependency Resolution

Dependencies Resolved

===============================================================================================================
Package Arch Version Repository Size

Installing:
percona-toolkit noarch 2.2.11-1 /percona-toolkit-2.2.11-1.noarch 5.5 M

Transaction Summary

Install 1 Package(s)
Upgrade 0 Package(s)

Total size: 5.5 M
Is this ok [y/N]: y
Downloading Packages:
warning: rpmts_HdrFromFdno: Header V4 DSA signature: NOKEY, key ID cd2efd2a

Public key for percona-toolkit-2.2.11-1.noarch.rpm is not installed